https://commits.kde.org/marble/a6f19270945ca10076bf0c640287c48814e3bde2

Fixed with https://commits.kde.org/marble/a6f19270945ca10076bf0c640287c48814e3bde2

Updated the patch as earthwings and shentey suggested.

Yes, I think shentey meant that. I got it wrong.
Looks good !

Yes, that's a better solution. Updated the diff.

Also, the method MarbleModelPrivate::assignFillColors(...) is used to assign inline style to each placemark OR to update the style of a already parsed data so that we don't have to parse the data again. A call to MarbleModelPrivate::assignFillColors(...) is done from MarbleModel::setMapTheme(...) to update the style of a GeoDataDocument.
So, if two themes have some common data, then while switching from one to another, we don't parse the data file again. We just update the style info of the already parsed file.
In case of assigning inline style to each placemark, this method is specific to political map. However, it's also used for others themes in case they have any common data

Suppose the method MarbleModelPrivate::assignFillColors(const QString &filePath) was called when the parsing for the file naturalearth/ne_50m_admin_0_countries.pn2 was done.